Various attempts to develop a vaccine to both the asexual systemic stage and the sexual entero-epithelial stage of the Toxoplasma life cycle have been reported over the last thirty years (Hermentin, K. and Aspock, H. (1988), Zbl. Bakt. Hyg. A, 269:423–436). These attempts can be grouped into the following categories: 1) immunization with whole killed organism, 2) immunization with selected antigens, either purified native or recombinant protein, 3) immunization with attenuated strains, and 4) immunization with irradiated organisms. Little success has been achieved with immunizations using whole killed organism (Frenkel, J. K. and Smith, D. D. (1982), Journal of Parasitology, 68:744–748). Partial success has been observed with the pure native protein P30 (Bulow, R., and Boothroyd, J. C. (1991), J. Immunol. 147:3496) and with selected fractions of parasite lysates (Lunden, A. Lovgren, K. Uggla, A., and Araujo, F. G.; (1993) Infection and Immunity, 61: 2639–2643). However, attempts with purified recombinant antigens have not been successful (Lunden, A., Parmley, S. F., Bengtsson, K. L. and Araujo, F. G. (1997) Parasitology Research, 83:6–9). Studies with irradiated organisms have reported 0–90% protection and are complicated by the uncertainty of truly inactivated irradiated preparations. Effective vaccines have been produced using attenuated strains. Two such mutant strains, ts-4 (Waldeland, H., Pfefferkorn, E. R., and Frenkel, J. K. (1983), Journal of Parasitology, 69:171–175) and S48 (Hartley, W. J. and Marshall, S. C. (1957), New Zealand Veterinary Journal, 5:119–124), successfully protect animals against the asexual systemic disease. These strains are delivered in the tachyzoite form and do not protect cats from oocyst shedding. Another strain, T-263 (Frenkel, J. K.; Pfefferkorn, E. R.; Smith, D. D.; and Fishback, J. L. (1991), American Journal of Veterinary Research, 52:759–763) is an oocyst minus strain, but was shown to progress through most of the entero-epithelial stages in the cat intestine. Exposure to this strain induces immunity in the cat to oocyst shedding upon subsequent challenge. There remains a need for an effective vaccine for prevention of the diseases caused by infection with Toxoplasma gondii. 